Deemed Spears' comeback record, Circus received generally favorable reviews from music critics upon its release; the production was complimented but lyrical content and Spears' vocal performance were met with ambivalence. A global commercial success, the album debuted atop the US Billboard 200 with first-week sales of 505,000 copies, becoming her fifth number-one album. Since then, it has been certified triple platinum by the Recording Industry Association of America (RIAA). By September 2009, the album had sold over four million copies worldwide. At the 52nd Annual Grammy Awards, its lead single "Womanizer" was nominated for Best Dance Recording.
Circus produced four singles. "Womanizer" debuted at number 96 on the US Billboard Hot 100 and ascended to the summit in its second week, registering the largest leap on the chart at the time. It became Spears' best-selling single in the country since her debut "...Baby One More Time" (1998). "Circus" debuted and peaked at number three on the Billboard Hot 100; consequently, Circus became Spears' first album since her debut ...Baby One More Time (1999) to have two top-ten singles. Subsequent singles "If U Seek Amy" and "Radar" peaked at numbers 19 and 88 on the Billboard Hot 100, respectively. To further promote the album, Spears embarked on the world tour The Circus Starring Britney Spears (2009).
Throughout 2007, Spears' professional endeavors were tremendously overshadowed by her personal struggles, including the aftermath of her vigorous partying and suffering from a nervous breakdown, during which she shaved her head to intense media scrutiny.[3][4] Despite the difficulties, Spears released her fifth studio album Blackout–considered her best and most influential work by numerous critics–in October.[5][6][7] However, it became her first studio album not to debut atop the US Billboard 200–debuting at number two–but nevertheless produced "Gimme More", Spears' first Billboard Hot 100 top-three hit since her debut "...Baby One More Time" (1998).[8][9] Upon its release, Spears' publicized behavior began clashing with her image; Stephen Thomas Erlewine of AllMusic said the album served as a soundtrack "for Britney's hazy, drunken days, reflecting the excess that's splashed all over the tabloids", while noting that the album had a coherence that the public Spears lacked.[10]
In January 2008, Spears refused to relinquish custody of her sons to her ex-husband Kevin Federline's representatives. She was subsequently hospitalized at Cedars-Sinai Medical Center after police that had arrived at her house noted she appeared to be under the influence of an unidentified substance. The following day, Spears's visitation rights were suspended at an emergency court hearing, and Federline was given sole physical and legal custody of their sons. She was committed to the psychiatric ward of Ronald Reagan UCLA Medical Center and put on 5150 involuntary psychiatric hold under California state law. The court placed her under a conservatorship led by her father Jamie Spears and attorney Andrew Wallet, giving them complete control of her assets.[11] She was released five days later,[12][13] while the conservatorship would not be terminated until November 2021, following Spears' highly publicized battle against her father and others involved in the conservatorship.[14] Soon after being placed under the conservatorship, work on Spears' sixth studio album commenced. Consequently, the release of "Radar" as the fourth single from Blackout was canceled so Spears could focus on Circus.[15]
"Once [Dr. Luke] and I were in the studio, he played me the music he was working on for [Britney], and we then based the song on what her life was like at the time and how people viewed her. It was a cool way to get people dancing and having fun, but also to have a slight message underneath of it all."
Producer Claude Kelly talks about the development, content and concept of Circus.[16]
In July 2008, it was confirmed that Spears was in the process of recording her sixth studio album.[17][18] "Radar" was originally included on Spears' fifth studio album Blackout (2007), and was recorded on November 8, 2006, the day after Spears filed for divorce from Kevin Federline, at the Sony Music Studios in New York City.[2] Alongside the announcement of Circus came the additional confirmation of the involvement of producers Sean Garrett, Guy Sigsworth, Danja and Bloodshy & Avant.[19] During its development, Garrett and vocal producer Jim Beanz complimented Spears's work ethic after her much-publicized personal struggles the previous year.[20][21] Spears co-wrote four tracks on the album and worked to develop a more pop-influenced record with collaborators she had worked with earlier in her career.[22] She stated that Circus marked the longest time she had spent recording an album, adding: "I think it is more urban [...] I'm writing every day, right here at the piano in this living room"[23] and also described the album as her best work to date.[24]
Producer Claude Kelly discussed the initial lack of concept for Circus, saying: "When I went in with [Dr. Luke] we knew we were going to maybe write something for [Britney], but there was no concept, it was just knowing her style and knowing what she does.[25]Max Martin, who frequently collaborated with Spears on her first three studio albums ...Baby One More Time (1999), Oops!... I Did It Again (2000) and Britney (2001), wrote and produced "If U Seek Amy". The Outsyders, an Atlanta-based production team, produced the lead single "Womanizer",[26] while Fernando Garibay worked on "Amnesia" and "Quicksand", neither of which made the standard edition track listing.[27] Danja reported that he worked on tracks at the Chalice Recording Studios in Los Angeles, while Spears recorded them at the Glenwood Place Studios in Burbank, California. Canadian trio Let's Go to War co-wrote and produced the track "Mmm Papi".[28]Guy Sigsworth, with whom Spears had previously collaborated with for her single "Everytime", produced two songs on the album: the ballads "My Baby" and "Out from Under", the latter of which is a cover song first performed by Joanna Pacitti for the soundtrack to the 2007 film Bratz.[29]Lil Jon,[30]Rodney Jerkins,[31]Sean Garrett,[32] and Taio Cruz[33] announced they were working with Spears, though their songs weren't included on the final track listing.
"Circus is a little bit lighter than Blackout. I think a lot of the songs I did at that time, I was going through a really dark phase in my life, so a lot of the songs reflect that. [...] But they're two totally different vibes. Blackout is a little bit more darker and edgier, and a little bit more urban."
Circus is predominantly a pop and dance record, described as a sequel to Spears' fifth studio album Blackout (2007).[34][35][36] Spears described the album as "lighter" than the urban-oriented Blackout.[22] The album has been compared to the works of Janet Jackson,[37]Eurythmics,[38] and New Order,[39] as well as the songwriting of Prince,[38]Leiber & Stoller and Phil Spector.[39] It incorporates lyrical themes previously acknowledged in Spears' work: "Circus" and "Kill the Lights" discuss fame, much like "Piece of Me" (2007),[36] while "Womanizer" and "Shattered Glass" talk about a womanizing man. Circus opens with its lead single "Womanizer", which features synth sirens with a repetitive chorus, and lyrically discusses a cheating man; it was described by Spears as a "girl anthem".[40] "Circus" addresses her feelings as an entertainer and performing, highlighted in the lines "All eyes on me in the centre of the ring just like a circus / When I crack that whip everybody gonna trip just like a circus". Its electronic dance elements were compared by PopJustice to those of Spears' earlier single "Break the Ice" (2008).[41] The ballad "Out from Under" incorporates acoustic guitar backings, while "Kill the Lights" is a dance-pop track speaking about Spears's conflict with paparazzi.[36] "Shattered Glass" utilizes dark electronic beats and details a non-repairable relationship. "If U Seek Amy" integrates "glam-rave" elements with traditional pop styles;[42] it gained controversy for its double entendre, where the title sounds phonetically like "F-U-C-K me".[43]
The electropop track "Unusual You" deals with a woman finding unexpected love. It has been compared to musical themes from the 1980s and 1990s, and has been noted as a "pulsating ballad", with the song also drawing comparisons to the "shimmering waterfall mood first popularized by Janet Jackson".[37][44][45] "Blur", which features Spears singing in a lower register, sees the inclusion of urban influences, and lyrically recalls the morning after a party: "Can't remember what I did last night/I gotta get my head right, where the hell am I? Who are you? What'd we do last night?";[46] it drew similarities to Spears' song "Early Mornin" from In the Zone (2003).[34] "Mmm Papi" draws elements from a 1960s go-gorock guitar, as well as Latin pop and dancehall themes.[44][47] Despite its "fun" nature, it was criticized for appearing to "revisit the Lolita persona of "...Baby One More Time".[48] It has been suggested that its lyrics deal with either Spears' father Jamie or paparazzo and Spears' ex-boyfriend Adnan Ghalib.[34] "Mannequin" is a trip hop-influenced dance-pop track; while being noted for its "risky" and "futuristic" nature, it has also been suggested that Spears' vocals sound "lifeless".[49] "Lace and Leather" is an electro-funk track which gained comparisons to "Control era Janet Jackson", Prince, and Vanity 6's works from the 1980s, and featured a then-unknown Kesha as a backing vocalist.[50][38][51] "My Baby", described as having a "faux-Janet Jackson vocal",[52] was written by Spears about her two sons Sean Preston and Jayden James Federline.[37][34]Circus closes with its bonus track "Radar", an electropop and Eurodisco song featuring distorted synthesizers emulating sonar pulses, which received comparisons to those of Soft Cell's "Tainted Love" (1981).[53][54] In its lyrics, Spears lets the subject know he is on her radar, while she lists the qualities the man has.[55]
Spears commented on the title of Circus: "I like the fact that you're always on the edge of your seat when you're at a circus. You're never bored [...] You're just really engulfed in what's going on around you. And you want to know what's going to happen next."[22] Spears also revealed she titled the album Circus due to her life being "a circus" at the time.[56] The album's cover artwork and booklet images were photographed by Kate Turning and feature Spears in circus-styled settings.[57] Spears revealed the album's cover alongside its track listing via her official website on October 31, 2008.[58]
In September 2008, it was announced Circus would be released on December 2, Spears' 27th birthday;[59] it shared its release date with the similarly titled album The Circus by British group Take That.[60] However, following unauthorized online leaks, imeem began streaming Circus on November 25.[61] To promote the album, Jive Records set up a hotline where fans could leave a message for Spears, some of which received a return phone call from her.[62] Some songs were previewed through the website of the New York radio station WKTU and Amazon.[63]MTV aired a 90-minute documentary Britney: For the Record on November 30, documenting her return.[64] In May 2009, Jive's official website held the "Global Fan-Fiction Contest", which required participants to submit a 200-word story based on one of the album's tracks.[65] The public was allowed to vote for their favorite short story, which would be produced into an animated music video. The winning story was based on the song "Kill the Lights", and the video premiered on July 27.[66]
Spears' live comeback and promotional activities for Circus began on November 6, 2008, with a cameo appearance at the Dodger Stadium show of Madonna's Sticky & Sweet Tour (2008–2009). Midway through the performance of "Human Nature", Spears joined Madonna on stage.[67] The week prior to the album's release, Spears performed in several countries as a part of the Circus Promo Tour. On November 27, Spears performed "Womanizer" live at the 2008 Bambi Awards in Offenburg, Germany, where she received an award for Best International Pop Star.[68] In addition, she performed the song on Star Academy in France the following day and on The X Factor in the United Kingdom on November 29.[69] Her performance on The X Factor was watched by an average of 11,880,000 citizens in the UK.[70] Spears premiered the second single "Circus" alongside "Womanizer" at the Big Apple Circus on Good Morning America on December 2.[71][72] On December 16, she performed on Nippon TV's Best Artist of 2008.[73]
While performing on Good Morning America on December 2, Spears announced her fifth worldwide concert tour, titled The Circus Starring Britney Spears. She initially revealed the first leg of 25 dates in the United States and two in the United Kingdom. Her longtime manager Larry Rudolph stated that the tour would "blow people's minds and promises to show Britney's fans something they will never forget",[74] later adding: "she goes full-speed the whole show — about an hour and a half. It's pretty intense. This is a full-blown, full-out Britney Spears show, It is everything everybody expects from her — and more!".[75] Spears also expressed excitement in including songs from Blackout into the setlist, as she did not tour to promote it.[22] The tour commenced on March 3, 2009, in New Orleans' New Orleans Arena and finished on November 29, in Adelaide's Adelaide Entertainment Centre. The tour consisted of four legs: two in North America, one in Europe and one in Oceania.[76] The stage was composed of three rings and set in-the-round to resemble an actual circus. Fashion designers Dean and Dan Caten created the costumes. A giant cylinder screen was set above the stage to showcase videos and backdrops. Effects were provided by Solotech. The setlist was composed generally from her albums In the Zone (2003), Blackout and Circus. In June, Spears announced she would tour Australia for the first time; she was also rumored to tour South America, though her manager Adam Leber denied this despite their efforts to do so.[77]
Controversy arose during the Australian leg of the tour after several fans walked out of the performances due to Spears' alleged lip-synching; such claims were later denied by Spears' management and promoters.[78] The tour was ranked as the fourth highest-grossing tour of the year in North America, becoming the highest-grossing tour of the year by a solo artist.[79] In February 2010, Pollstar released their Top 50 Worldwide Concert Tours of 2009; the Circus Starring Britney Spears was ranked as the world's fifth highest-grossing tour of the year, with a gross of $131.8 million.[80] In May 2010, Hollyscoop ranked the tour at number five on their "15 Most Profitable Female Tours Ever" list.[81]
"Womanizer" was released as the lead single from Circus on September 26, 2008. The song was met with positive response from critics, who complimented its hook and empowering lyrics, deeming it a return of form and a "comeback" single for Spears.[82] It debuted at number 96 on the US Billboard Hot 100 before leaping to the summit the following week, breaking the record for the largest leap on the chart.[83][l] The song has sold over 3,500,000 digital downloads in the United States.[85] Internationally, it reached number one in Belgium, Canada, Croatia, Denmark, Finland, France, Israel, Norway, Sweden and Turkey, and on the European Hot 100 Singles.[86][87][88][89][90] At the 52nd Annual Grammy Awards (2010), the song was nominated for Best Dance Recording.[91] Its accompanying music video premiered on October 18, as a spiritual sequel to "Toxic" (2004); both videos were directed by Joseph Kahn. It portrays Spears as a woman who disguises herself in different costumes and follows her boyfriend through his daily activities to expose him in the end.[92] The video won Best Pop Video and was nominated for Video of the Year at the 2009 MTV Video Music Awards.[93] "Womanizer" remains one of Spears' biggest hits and has been covered by numerous other artists.[94]
"Circus" was released as the second single from Circus on December 2, 2008.[95] It debuted and peaked at number three on the US Billboard Hot 100.[96] The song has sold over 3,200,000 digital downloads in the US.[85] Internationally, it peaked atop the Türkiye Top 20 and within the top ten in Australia, Bulgaria, Canada, Denmark, Hungary, Israel, New Zealand, Scotland and Sweden.[97][98][99][100] Its Francis Lawrence-directed accompanying music video portrays Spears as a ringleader of a circus accompanied by different performers, and features scenes of Spears in different circus settings. The video received positive reviews from critics, but was criticized for featuring "cruelly trained animals"; however, those claims were dismissed.[95] It won a Best Video award on Fuse TV,[101] and was nominated for three MTV Video Music Awards in 2009.[102]
"If U Seek Amy" was released as the third single from Circus on March 10, 2009. Due to the song's double entendre in the chorus, the Parents Television Council (PTC) threatened to file indecency complaints with the Federal Communications Commission (FCC) against any station that played the song between 6 a.m. and 10 p.m.[103] A clean edit of the song, titled "If U See Amy", was later sent to radio by Jive Records.[103] The song peaked at number 19 on the US Billboard Hot 100,[104] making Circus Spears' first album since ...Baby One More Time to produce three top-20 singles. Internationally, it peaked atop the Brasil Hot 100 Airplay, whilst reaching the top ten in Belgium, Israel, Malaysia and Mexico.[105][106][107][108] Its Jake Nava-directed accompanying music video was released on March 12, and depicts Spears poking fun at American culture.[109]
"Radar" was originally included on Spears' fifth studio album Blackout (2007) and set to be released as its fourth single. However, its release was canceled when Spears began work on Circus, and it was instead released as a promotional single in 2008.[15] It was subsequently included as a bonus track on Circus and was released as its fourth single on June 5, 2009. The song originally entered the US Digital Songs at number 52 due to digital downloads from Blackout. After being confirmed as a single, entered the US Billboard Hot 100 at number 90, peaking at number 88 the following week; it became Spears' lowest-peaking US-released single on the chart.[110] Its Dave Meyers-directed accompanying music video portrays Spears as an aristocrat at a polo mansion, who's involved in a love triangle with two polo players.[111]
Despite not being released as singles, several tracks from Circus appeared on Billboard's component charts upon its release. "Shattered Glass", peaked at number 70 on the US Billboard Hot 100, higher than the actual single "Radar". It additionally peaked at number 29 on the US Digital Songs and number 75 on the Canadian Hot 100.[112][87] The song also entered the US Pop 100 chart, peaking at number 57.[113] "Lace and Leather" and "Mmm Papi" peaked at numbers 84 and 94 on the Pop 100, respectively.[113] "Out from Under" debuted at number 40 on the Swedish Singles Chart on August 14, 2009, reaching number 32 the following week and staying on the chart for five weeks.[114]
Upon its release, Circus received generally favorable reviews from music critics. At Metacritic, which assigns a normalized rating out of hundred to reviews from mainstream critics, Circus received an average score of 64, based on 22 reviews, indicating "generally favorable reviews".[124] Stephen Thomas Erlewine provided a favorable review, describing it as a "friendly remake of the hedonistic Blackout", but preferred its predecessor for being more "sleek or addictive" than Circus.[117] Genevieve Koski of The A.V. Club appreciated that Spears appeared to "put some real effort into her Circus performances", rather than seeming "flat-sounding" as she felt Blackout had.[125] Writing for Digital Spy, Nick Levine opined that Spears "sounds more confident" than she had on Blackout.[126] While Chris Willman from Entertainment Weekly appreciated the overall production of Circus, he was critical of Spears' recently established pattern of "putting out albums with titles that promise more self-revelation than she's ultimately able to provide."[44]Robert Christgau gave Circus a two-star honorable mention, stating that it was "still fun more often than not".[127] Jon Pareles of The New York Times expressed his enjoyment of the "crisp" material that incorporated "catchy melodic interludes".[128] Caryn Ganz from Rolling Stone opined that the "clubby, adventurous pop" included on the album could have been a satisfactory successor to her fourth studio album In the Zone (2003).[34]
Writing for USA Today, Steve Jones applauded Spears for being "resilient" and "[knowing] who she is as a singer" and not "[wasting] time searching for artistic direction or overthinking her appeal."[123]The Village Voice considered Circus "no better or worse than Janet Jackson's dominatrix-lite Discipline."[129] Alexis Petridis of The Guardian gave a more mixed review, suggesting that Spears "frequently sounds disconnected, even a bit bored" throughout the record, whereas Blackout was a "relentless, risky album made by a woman whose obituary was apparently being prepared by Associated Press."[49] A writer for The Independent gave a negative review, opining that Spears' vocal delivery sounded emotionless in mid-tempo and ballad-paced tracks.[118]Slant Magazine's Eric Henderson shared a similar sentiment, suggesting that the album's "self-actualization" gave off a "hollow" feel through the majority of the record.[122] Ann Powers from Los Angeles Times felt that Circus served as a "bang-up job" of stating that "Spears is still a young woman trying to manage an impossible situation."[119] Writing for NME, Hamish MacBain was disappointed that "Spears is quite simply rubbish at being sexy", adding that Circus is the "umpteenth attempt to turn the perceived chaos of Britney's transition to adulthood – she's 27 next week! – into sleazy, raunchy, dirrty adult-pop product."[120]
In the United States, Circus debuted atop the Billboard 200, with first-week sales of over 505,000 copies. It registered the second biggest debut-week sales of 2008 for a female artist, only behind Taylor Swift's Fearless.[138] The album spent nine weeks within the top ten, making it Spears's longest-running top-ten album since Oops!... I Did It Again (2000), which spent 23 weeks inside the top ten.[139][140] It was certified platinum by the Recording Industry Association of America (RIAA) on January 29, 2009.[141] The album placed sixth on the year-end Billboard 200 for 2009.[142] According to Nielsen SoundScan, the album had sold 1.7 million copies in the US by March 2015.[143] With over 51,000 units sold in its first week, the album opened atop the Canadian Albums Chart; it marked her highest first-week sales in Canada since Oops!... I Did It Again, which sold 95,000 copies.[144] In less than a month, it became the ninth best-selling album of 2008 in the country, selling 143,000 copies, and one of the top ten best-selling digital albums of the year with over 10,100 downloads.[145] In March 2009, the album was certified triple platinum by the Canadian Recording Industry Association (CRIA).[146] In Mexico, Circus debuted atop the international album chart and at number three on Top 100 Mexico, selling over 46,000 copies and being certified gold by the Asociación Mexicana de Productores de Fonogramas y Videogramas (AMPROFON) in its first week.[147][148]
"There is no misinterpreting the lyrics to this song, and it's certainly not about a girl named Amy. It's one thing for a song with these lyrics to be included on a CD so that fans who wish to hear it can do so, but it's an entirely different matter when this song is played over the publicly-owned airwaves, especially at a time when children are likely to be in the listening audience."
—PTC's president Tim Water on the controversy over "If U Seek Amy" lyrics.[162]
Circus and endeavors during its promotional campaign were subjects of various controversies. Controversy first arose on December 5, 2008, when Australian music site Undercover.com.au reported a complaint on the lyrical content of "If U Seek Amy" from Leonie Barsenbach, a housewife from Sydney, who stated: "I was astonished and totally taken aback when I heard my 5 and 7-year-old kids walking around the house singing 'F-U-C-K' ... When I asked them what it was, they told me it was Britney Spears. I was horrified. I got them the Circus album but there was no warning on it ... It is extremely offensive. I feel deceived."[163][164]Rolling Stone writer Daniel Kreps defended Spears, arguing that parents should have been aware of her lyrical themes.[165] After the song was announced as the third single from the album in January 2009, American radio stations were unsure about playing it due to its double entendre in the chorus; WFLZ-FM produced their own edit of the song, titled "If U See Amy".[166] Shortly after, the Parents Television Council (PTC) threatened to file indecency complaints with the Federal Communications Commission (FCC) against any station that played the song between 6 a.m. and 10 p.m.[167] RBR.com reported that "interestingly, Circus was reviewed by Common Sense Media, another organization whose mission is to help parents manage their children's media consumption. It rated it appropriate for age 13 and up, but made no specific mention of 'If U Seek Amy'. Even more interestingly, reputed incoming FCC Chair Julius Genachowski is a founding board member of Common Sense."[168]
The accompanying music video for the title track of Circus caused further controversy due to its use of exotic animals. On December 9, 2008, animal rights organization People for the Ethical Treatment of Animals (PETA) issued a press release condemning Spears for using "cruelly trained lions and elephants" and demanding her to "stop using exotic animals in her videos and concerts once and for all". Spears had previously received criticism from the organization when she used an albino python and a caged tiger during a performance of "I'm a Slave 4 U" at the 2001 MTV Video Music Awards. Kari Johnson from Have Trunk Will Travel responded by saying: "[the company] has never issued a written endorsement, nor does it condone using electrical devices to discipline and control elephants except in situations where elephant or human safety is at risk. [...] The American Humane Association monitors animal action in film and television. A representative was on the set of the Britney Spears 'Circus' video with our elephants, Tai and Kitty, to ensure their safety and welfare [...] Britney, the director, producers and the entire crew were respectful of the elephants' needs and comfort and a pleasure to work with."[169]
The Australian leg of the album's accompanying tour the Circus Starring Britney Spears caused controversy following its opening show in Perth on November 6, 2009, when The Advertiser writer Rebekah Devlin reported that a number of fans had walked out of the show; they were apparently "disappointed" and "outraged" regarding Spears' lip syncing and subdued dancing.[170] Australian tour promoter Paul Dainty denied the allegations,[171] while Spears' manager responded via his Twitter account by saying: "It's unfortunate that one journalist in Perth didn't enjoy the show last night. Fortunately the other 18,272 fans in attendance did"; Spears' official website also posted a list of positive reviews from a number of fans.[172]
Benny Blanco – drums (tracks 2, 5 and 11), keyboards (tracks 2, 5 and 11), production (tracks 2, 5 and 11), programming (tracks 2, 5 and 11), songwriting (tracks 2, 5 and 11)
Bloodshy & Avant – bass (tracks 7 and 13), engineering (tracks 7 and 13), guitar (tracks 7 and 13), keyboards (tracks 7 and 13), mixing (track 7), production (tracks 7 and 13), programming (track 7 and 13), songwriting (tracks 7 and 13)
David Boyd – additional engineering (track 10)
Luke Boyd – backing vocals (track 8), songwriting (track 4)
Nikesha Briscoe – production (track 1), songwriting (track 1)
Jim Carauna – additional engineering (track 13)
Chad Carlisle – engineering assistance (track 2)
The Clutch – engineering (track 13), production (track 13), songwriting (track 13)
Dr. Luke – drums (tracks 2, 5 and 11), guitar (tracks 2, 5 and 11), keyboards (tracks 2, 5 and 11), production (tracks 2, 5 and 11), programming (tracks 2, 5 and 11), songwriting (tracks 2, 5 and 11)
Pati Dubroff – make-up
Bojan "Genius" Dugić – engineering (track 1)
Laura Duncan – styling
Eric Eylands – engineering assistance (tracks 5, 6, 9 and 11)
* Sales figures based on certification alone. ^ Shipments figures based on certification alone. ‡ Sales+streaming figures based on certification alone.
^The deluxe edition cover features the red and blue colors of the frame in vice-versa.[1]
^"Radar" originally appeared on Spears' fifth studio album Blackout (2007), hence it was recorded earlier than the rest of Circus, being recorded on November 8, 2006 at the Sony Music Studios in New York City.[2]
^ abc"Lighter, brighter Circus". Canoe. December 2, 2008. Archived from the original on July 11, 2012. Retrieved December 2, 2008.{{cite web}}: CS1 maint: unfit URL (link)
^ abcdWillman, Chris (November 29, 2008). "Circus Review". Entertainment Weekly . Archived from the original on December 2, 2013. Retrieved November 28, 2013.
^Willman, Chris (November 29, 2008). "Circus Review". Entertainment Weekly. Archived from the original on January 12, 2012. Retrieved August 7, 2011.
^"Circus Review". NME. November 28, 2008. Archived from the original on January 22, 2009. Retrieved September 6, 2009.
^"Britney Spears". Billboard. Archived from the original on February 6, 2023. Retrieved February 9, 2023. Note: Select a chart listed inside the drop-down menu.
^ abStephen Thomas Erlewine. "Circus: Britney Spears". AllMusic. Rovi Corporation. Archived from the original on October 13, 2017. Retrieved November 28, 2013.
^Williams, John (December 10, 2008). "Britney returns to No. 1". Canoe Jam!. Archived from the original on May 26, 2012. Retrieved June 20, 2009.{{cite web}}: CS1 maint: unfit URL (link)
^"Czech Albums – Top 100". ČNS IFPI. Note: On the chart page, select 50.Týden 2008 on the field besides the words "CZ – ALBUMS – TOP 100" to retrieve the correct chart. Retrieved December 22, 2016.
^オリコン年間 CDアルバムランキング 2009年度 [Oricon Annual CD Album Ranking 2009]. Oricon (in Japanese). Archived from the original on December 22, 2016. Retrieved December 22, 2016.
^"Los Más Vendidos 2009"(PDF). Asociación Mexicana de Productores de Fonogramas y Videogramas (in Spanish). Archived from the original(PDF) on February 15, 2010. Retrieved March 11, 2010.
^"ブリトニー・スピアーズ「Circus」を iTunes で" (in Japanese). iTunes Store (JP). Apple Inc. November 28, 2008. Archived from the original on October 14, 2017. Retrieved October 13, 2017.